Combustion device

ABSTRACT

The present invention pertains to a combustion device which is mounted to a wood boiler or the likes and generates high thermal power while decreasing soot by means of a simple structure. According to the present invention, a combustion device comprises; a main body having a porous plate which is formed inside and on which injected fuel is stacked; a fuel injection section communicating with one side of the upper portion of the main body; a first air supply section communicating with the lower portion of the porous plate of the main body and supplying air; an ignition section formed to be adjacent to the porous plate and igniting the fuel; a flame discharge section extending from the other side of the upper portion of the main body and discharging the flame and heat caused by the combustion; a cyclone section formed in the shape of a short cylinder and expanding in a lateral direction from the periphery of the flame discharge section so as to partially expand the path of the flame discharge section; and a second air supply section communicating with one side of the periphery of the cyclone section and supplying air to the cyclone section in a tangential direction.

TECHNICAL FIELD

The invention relates to a combustion device, and more particularly to acombustion device which has a simple structure and burns wood chips,wood pellets or other fuel to achieve high heat efficiency and strongthermal power and generate less soot or air pollution.

BACKGROUND ART

The combustion devices or burners which use wood fuels such as sawdust,wood chips or wood pellets produced by extruding the wood chips arewidely used on the boiler, stove, heater or hot air generator. To usethe burner of this type, the user should pour the sawdust, wood chips orwood pellets on the porous plate or grate in the body of the burner andset fire and supply air on them. In this case, if the supplied air isnot sufficient, the fuel will not be burned completely, and much sootwill be generated and the sufficient thermal power may not be attained.Contrarily, if the air is supplied powerfully for sufficient oxygen,then the unburned particles of wood fuel on the grate or the soot of theincompletely burned fuel particles will fly and be scattered outside theburner by the powerful air blow, which results in the insufficientthermal power or low heat efficiency of the combustion device, and thesurrounding air will be polluted owing to the scattered unburned dust orsoot of the wood fuel.

DISCLOSURE Technical Problem

The invention is suggested to solve the above mentioned problems of theconventional combustion devices, and the object of the invention is toprovide a new combustion device which has a simple structure and burnswood chips, wood pellets or other fuel to achieve high heat efficiencyand strong thermal power and generate less soot or air pollution.

Technical Solution

To attain the above object of the invention, according to an aspect ofthe invention, there is provided a combustion device comprises; a mainbody having a porous plate which is formed inside and on which injectedfuel is stacked; a fuel injection section communicating with one side ofthe upper portion of the main body; a first air supply sectioncommunicating with the lower portion of the porous plate of the mainbody and supplying air; an ignition section formed to be adjacent to theporous plate and igniting the fuel; a flame discharge section extendingfrom the other side of the upper portion of the main body anddischarging the flame and heat caused by the combustion; a cyclonesection formed in the shape of a short cylinder and expanding in alateral direction from the periphery of the flame discharge section soas to partially expand the path of the flame discharge section; and asecond air supply section communicating with one side of the peripheryof the cyclone section and supplying air to the cyclone section in atangential direction.

According to another aspect of the invention, the flame dischargesection has a tapered inner portion between the main body and thecyclone section to restrict the backward air flow.

According to another aspect of the invention, the fuel injection sectionis formed in the shape of tube, and a backfire prevention air injectionhole is formed on the periphery of the fuel injection section.

According to another aspect of the invention, small holes are formed onthe periphery of the cyclone section to exhaust the ash generated aftercombustion.

Advantageous Effects

According to the invention, as the fuel stacked on the porous plate isburned by the air supplied through the first air supply section and theflame and heat are discharged through the flame discharge section, eventhough the air is supplied powerfully for sufficient oxygen through thefirst air supply section, so the unburned particles of fuel or the sootof the incompletely burned fuel are to fly and be discharged through theflame discharge section, they should be induced toward the cyclonesection by the centrifugal force of the tangential air inflow throughthe second air supply section and circulate inside the cyclone sectionand are burned again by use of the oxygen in the additional air from thesecond air supply section, which results in almost complete combustionand prevents the unburned fuel particles or the soot of incompleteburned fuel from discharging through the flame discharge section.Therefore, the combustion device according to the invention is possibleto achieve an effective combustion device having higher thermal powerand higher heat efficiency with least environmental pollution owing tothe discharged unburned fuel particles, soot or smoke.

In addition, as the flame discharge section has a tapered inner portionbetween the main body and the cyclone section to restrict the backwardair flow, the circulating air in the cyclone section would flow toexhaust outward rather than flow backward into the main body, so thatthe flame and air should flow outward smoothly.

In addition, as the fuel injection section is formed in the shape oftube and a backfire prevention air injection hole is formed on theperiphery of the of the fuel injection section, the flame in the mainbody of the burner is not prevented from backfiring through the fuelinjection section.

In addition, as small holes are formed on the periphery of the cyclonesection, the small amount of ashes created after the second burning ofthe incompletely burned fuel and soot could be emitted outward, so theaccumulation of the ash inside the cyclone section may be prevented.

DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the invention will becomemore apparent by describing a preferred embodiment with reference to theaccompanying drawings in which:

FIG. 1 is a perspective view of the preferred embodiment of theinvention.

FIG. 2 is a sectional view of the above embodiment of the invention.

FIG. 3 is an example of the hot air generator which the invention isapplied to.

BEST MODE

Hereinafter, a preferred embodiment of the invention will be describedwith reference to the accompanying drawings. FIG. 1 is a perspectiveview of the embodiment of the invention and FIG. 2 is a sectional viewof the embodiment of the invention. As shown, the combustion device 2 ofthe invention comprises a case type main body 10, a porous plate 12 orgrate placed horizontally in the lower part of the main body 10, and afirst air supply section 18 formed beneath the porous plate 12 throughwhich the outer air inflows. A fan or blower may be connected to thefirst air supply section 18 to supply the air into the main body 10. Anignition section 20 is formed above the first air supply section 18, orright above the porous plate 12. A proper ignition means may be attachedto this ignition section 20 such as a gas torch or an electrical heater.

A fuel injection section 14 is formed on one side of the upper portionof the main body 10. This fuel injection section 14 may have variousstructures, but it is preferable to have space between the inlet of thefuel injection section 14 and the main body 10, so a lengthy tubularfuel injection section is desirable. A backfire prevention air injectionhole 15 is formed in the periphery of the fuel injection section 14.This backfire prevention air injection hole 15 is connected to the fuelinjection section 14 so as to direct the air toward the main body 10.Accordingly if the pressured air is injected into the backfireprevention air injection hole 15, the flame in the main body 10 isprevented from backfiring through the fuel injection section 14.

A cylindrical flame discharge section 24 extends from on the other sideof the main body 24. This flame discharge section 24 discharges theflame and heat created in the main body 10 during the combustion of thefuel and introduces them to necessary utilities or a heat exchanger. Inthis preferred embodiment, a short cylindrical cyclone section 30 isformed at the middle portion of the flame discharge section 24, whichexpands in a radial direction from the periphery of the flame dischargesection 24. Due to this cyclone section 30, the exhausting sectionalarea of the flame discharge section 24 is enlarged in a short distance.And a second air supply section 32 is formed on the periphery of thecyclone section 30, which communicates with cyclone section 30 in atangential direction. A fan or blower may be connected to the second airsupply section 32 to supply strong air flow. As a result, the strongcirculating air flow is formed inside the cyclone section 30.

According to the above structure of the cyclone section 30, even thoughsufficient air may be supplied powerfully from the first air supplysection 18 to the main body 10 for sufficient oxygen, and it may causethe unburned fuel particles and the soot of the incompletely burned fuelto be discharged from the flame discharge section 24, the centrifugalforce due to the circulating air created in the cyclone section 30 dueto the air flow from the second air supply section 32 will induce themtoward the periphery of the cyclone section 30, and those fuel particlesor soot will be retained and circulate in the cyclone section 30 andwill be secondly burned with the refilled flesh air supplied from thesecond air supply section 32. Therefore, the unburned fuel particles orthe soot of the incompletely burned fuel may not be discharged directlyfrom the flame discharge section 24, but they will be burned outsecondly by the additional fresh air from the second air supply section32, which will result in the almost complete combustion of the burnerand the least emission of air polluting particles such as unburned fuelparticles or soot of the incompletely burned fuel.

According to the invention, the flame discharge section 24 is providedwith a tapered inner portion 34 at the inner side of the cyclone section30 facing the main body 10 to restrict the backward air flow. Thetapered inner portion 34 reduces the sectional area of the flamedischarge section 21 gradually from the main body 10 to the inlet of thecyclone section 30, so that when the circulating air exits from thecyclone section 30, the exiting air may be restricted to flow backwardlyinto the main body 10, but it may be smoothly introduced to flow towardthe outside of the flame discharge section 24.

And, plural small holes 31 are formed on the periphery of the cyclonesection 30, which enable the ashes created during the secondly burningof the unburned fuel particles or incompletely burned fuel in thecyclone section 30 by the additional fresh air from the second airsupply section 32 to be emitted from the cyclone section 30. Therefore,the burned residuals such as ashes may not be remained in the cyclonesection 30.

In addition, the fuel injection section 14 is formed in the shape oftube, and a backfire prevention air injection hole 15 is formed on theperiphery of the fuel injection section 14. The backfire prevention airinjection hole 15 is connected to the fuel injection section 14inclining toward the main body 10. By injecting the pressured air, theflame in the main body 10 is prevented from backfiring through the fuelin the tubular fuel injection section 14. Preferably regulating valvesmay be attached at the first air supply section 18, the second airsupply section 32 and the backfire prevention air injection hole 15 tocontrol the volume of the air flow.

FIG. 3 shows the example of the hot air generator 1 which uses thecombustion device of the invention as heat source. The hot air exhaustedfrom the combustion device 2 of the invention is induced through theheat exchanger 4 comprising of fin tubes and delivered to demandingfacilities. The invention may be applied as various uses such as a hotair generator, a boiler, heater, stove and others.

As described above, the invention has been described with respect toparticularly preferred embodiments. However, the invention is notlimited to the above embodiments, and it is possible for one who has anordinary skill in the art to make various modifications and variations,without departing off the spirit of the invention. Thus, the protectivescope of the invention is not defined within the detailed descriptionthereof but is defined by the claims to be described later and thetechnical spirit of the invention.

1. A combustion device comprises; a main body having a porous platewhich is formed inside and on which injected fuel is stacked; a fuelinjection section communicating with one side of the upper portion ofthe main body; a first air supply section communicating with the lowerportion of the porous plate of the main body and supplying air; anignition section formed to be adjacent to the porous plate and ignitingthe fuel; a flame discharge section extending from the other side of theupper portion of the main body and discharging the flame and heat causedby the combustion; a cyclone section formed in the shape of a shortcylinder and expanding in a lateral direction from the periphery of theflame discharge section so as to partially expand the path of the flamedischarge section; and a second air supply section communicating withone side of the periphery of the cyclone section and supplying air tothe cyclone section in a tangential direction.
 2. A combustion device ofclaim 1, wherein the flame discharge section has a tapered inner portionbetween the main body and the cyclone section to restrict the backwardair flow.
 3. A combustion device of claim 1, wherein the fuel injectionsection is formed in the shape of tube, and a backfire prevention airinjection hole is formed on the periphery of the fuel injection section.4. A combustion device of claim 2, wherein the fuel injection section isformed in the shape of tube, and a backfire prevention air injectionhole is formed on the periphery of the fuel injection section.
 5. Acombustion device of claim 1, wherein small holes are formed on theperiphery of the cyclone section to exhaust the ash generated aftercombustion.
 6. A combustion device of claim 2, wherein small holes areformed on the periphery of the cyclone section to exhaust the ashgenerated after combustion.